Electronic-display instrument panels for automotive vehicles

ABSTRACT

This instrument panel comprises at least two small rules or display panels of which one comprises a luminous member for displaying the values supplied from a pulse counter and the other comprises pilot-lamps carrying illuminated symbols corresponding to the magnitudes displayed for the various functions or physical conditions being measured, the device further comprising an electronic assembly consisting of a member adapted to emit periodic signals, of members for converting the signals transmitted from pickups or probes into modulated-frequency pulses, of switching members, of further display apparatus, of apparatus for adjusting the luminous intensity and of apparatus for actuating alarm devices.

This is a continuation of application Ser. No. 504,239 filed Sept. 9,1974, now abandoned, which in turn is a continuation of application Ser.No. 294,997 filed Oct. 4, 1972, now abandoned.

The present invention relates in general to instrument panels, notablyfor automotive vehicles, and has specific reference to an improvedelectronic panel for displaying the values measured by the apparatususually associated with instrument panels.

Conventional instrument panels of motor vehicles incorporate variousmeasuring and control apparatus for measuring or displaying differentmagnitudes necessary to enable the driver to properly control hisvehicle. The main instruments are the speedometer, the oil pressuregauge, the thermometers indicating the temperature of the engine coolingfluid, the inner and outer temperatures, the battery voltmeter, theammeter, the fuel guage indicating the amount of petrol in the tank,etc.

A major inconvenience of these conventional instrument panels is on theone hand their generally poor position with respect to the field ofvision of the driver who is compelled to divert his vigilant andcontinuous watching of the road ahead of the vehicle for reading thedata displayed by the various dials, and on the other hand the fact thatmost instruments are sensitive to shocks and vibration generated duringthe vehicle operation, so that misreadings may occur.

Optical devices have already been proposed for transposing ortransfering the image of the display dial or dials into a substantiallyvertical plane lying in the direct field of vision of the driver.However, these devices are not only hardly applicable to all theinstruments but also are used almost exclusively for reading thespeedometer dial, without eliminating the serious inconvenience ofshocks and vibration.

Other devices intended for improving the visibility of the datacorresponding to the measured values are also known; they comprise as arule luminous units disposed on a row and responsive to the action of anelectric field associated with the measuring instrument and varying as afunction of the measured magnitudes.

Thus, a kind of luminous scale travelling according to the intensity ofthe electric field and giving fugitive measurement images is obtained.

According to a known device described and illustrated in the French Pat.No. 707.43158 of Dec. 1, 1970 filed by the same Applicants, a pluralityof luminous members disposed on one or two rows constitute scales givingfugitive measurements of various magnitudes to be measured, thesuccessive luminous members being energized by static switchesresponsive to voltage thresholds determined by pickups or detectorsassociated with the specific functions to be checked or controlled.

These last two types of known devices give measured data only onluminous scales, thus excluding any direct digit display; moreover, theindications relating to different functions appear separately for eachfunction on a different scale disposed at a different location, so thatthe driver must perform a switching operation for each indication otherthan the speedometer indication.

It is the primary object of the present invention to provide aninstrument panel eliminating all the above-listed inconveniences andcomprising at the desired location within the field of vision of thedriver an instrument panel of reduced dimensions on which a singleluminous digit display member is adapted to translate through a suitabledecoding system all the magnitudes to be measured on board a motorvehicle, and wherein the values corresponding to the measurement of afunction, for example the speed of the vehicle, appear permanently,whereas selected sequences of momentary values concerning themeasurement of other functions and/or physical conditions appear only onthe driver's request, said digit display being associated with alarmmeans and adapted if desired to be combined with luminous scales.

This instrument panel displaying the values of measurements or signalsemitted from pickups or probes for indicating specific functions orphysical conditions, is characterized essentially in that it comprisesat least two "rules" or display panels advantageously incorporated in asingle dial of which the first rule comprises a member for the luminousdisplay of values transmitted from a pulse counter and the second onecontains pilot lights bearing conventional illuminated signs or symbolsfor the displayed magnitudes of the various measured functions orconditions, this device further comprising a member adapted to emitperiodic signals during which the pulses received from the pickup arecounted; members for converting the signals emitted by said pickups andprobes into modulated-frequency pulses transmitted to the counter,switching means for transmitting either automatically and permanentlythe information from a single function or, on request of the driver ofthe vehicle, selected sequences of data concerning several functions orconditions, means for displaying the signs and symbols, means forregulating the luminous intensity of the display, and means forenergizing light and/or sound alarm devices at predetermined thresholdsof the values displayed for the various functions.

Other features and advantages of this invention will appear as thefollowing description proceeds with reference to the attached drawingsillustrating diagrammatically by way of example a typical form ofembodiment of an instrument panel.

In the drawings:

FIG. 1 is a front view of a frame comprising display rules;

FIG. 2 is a block diagram of the complete instrument panel, and

FIG. 3 is a typical form of embodiment showing the combination of aninstrument panel according to this invention with a rear view mirror.

Referring first to FIG. 1, the instrument panel illustrated comprises apair of display panels or rules 1 and 2 assembled through a frame 3. Thelower rule 1 comprises a recessed window in which a luminous digitdisplay is caused to appear, for example by means of an alpha-numericsystem comprising electroluminescent diodes, or any other suitable andsimilar system, such as for instance cold-cathode display or indicatingtubes, or liquid crystals (organic solution) having a variablereflecting power when illuminated.

The upper rule 2 comprises means for displaying the luminous images ofsymbols corresponding to the various functions and physical conditionsto be measured. Thus, for example, 5a designates the signal lampcarrying the oil pressure symbol, 5b is a thermometric symbol for thetemperature of the engine cooling fluid, 5c shows a flash symbolcorresponding to the battery voltage, 5d shows a jerrican symboldesignating the fuel level in the tank, 5e is the symbol correspondingto the temperature inside the vehicle, and 5f is a snow-man symbolizingthe external temperature.

The numeric display at 4 constantly indicates the vehicle speed inm.p.h. (or km.p.h.) in the form of a figure (in the case of speeds below10) or two or three figures for higher speeds. This display is obtainedeither through a luminescent-diode alpha-numeric system, or through anyother similar system such as cold-cathode tubes, illuminated liquidcrystals (organic solution) of which the reflection power varies as afunction of the illumination, as suggested hereinabove.

The same display system is used for displaying, on request of the driverand by discontinuing the speed indication, one or a plurality of datasequences corresponding to measurements made of the various functionsmentioned hereinabove; this display may be obtained for example by thedriver, by simply actuating a switch, as will be explained presently.

At the same time with the display at 4 of the values of the variousmeasured magnitudes, possibly with a decimal comma and/or a conventionalsign (such as "°" for the degrees centigrade), the pilot lamp 27 of thecorresponding symbol (5a . . . 5f) of rule 2 is illuminated. Theseimages, possibly completed by the corresponding units of measure, may bedisplayed by means of a special alpha-numeric system, and a monochromeor multicolored mask 28 bearing the aforesaid symbols may cover saidrule, so that only the symbol corresponding to the desired sequenceappears simultaneously with the corresponding display of the measuredvalue on rule 1. At the end of the sequences, the speedometer indicationappears again in the recessed window 4.

In case of alarm, i.e. when the predetermined function threshold valuehas been overstepped in one or the other direction, (for example thefuel level in the tank or the temperature of the engine cooling water),the value of the function concerned and its symbol are displayed bypriority and the corresponding pilot lamp of rule 2 begins to flicker. Asound signal may also be energized at the same time for attracting morethe driver's attention.

Referring now to FIG. 2, showing the block diagram of the instrumentpanel of this invention, it will be seen that the panel equipmentcomprises a first interface 6 receiving the electric signals from aspeed pickup unit 7 of any known type, and modulates same; the signals,at a frequency proportional to the vehicle speed, are fed permanently toa static first switching member 8 and applied thereby to a pulse counter9 of the integrated-circuit type. A master-clock 10 connected to saidcounter emits square waves of constant duration; the pulses received bythe counter are counted during these square waves, the number of pulsescorresponding of course to the vehicle speed.

The counter 9 is provided with an alpha-numeric display system 11 of theelectro-luminescent diode type, or of the cold-cathode tube type, asalready mentioned hereinabove.

On the other hand, the probes or pickups designated in general by thereference numeral 12 convert into variable voltages the measures of thephysical condition or the various functions to be checked. Thesevoltages are transmitted through interfaces 13 to a multiple secondswitching member 14. When the driver of the vehicle actuates thesequence call device 15, for example a simple push-button, the latteractuates or energizes a so-called "sequence" device 16 connected to themaster-clock 10 and to said switching system 14, and, by means of thesignal received from the master-clock, starts successively the switchingof the various measure sequences at adjustable time intervals. Thus, thedriver can call at any time either a sequence of all the data, or forexample two sequences of three data each. The voltage signals of thesuccessive sequences are fed to a digit voltmeter 17 comprising anoscillator and receiving on the other hand the signals from themaster-clock. This voltmeter converts the voltages fed thereto intopulses of which the frequency is proportional to the voltage fed to thevoltmeter. The pulses from this voltmeter 17 are then fed to the firstswitching system 8 which is actuated and thus discontinues thetransmission of signals from the speed pickup unit 7 and thecorresponding display, and transmits the successive pulses to thecounter 9 which displays them in succession at predetermined timeintervals. At the same time, the switching member 14 illuminates insuccession the symbol pilot lamps 5a to 5f of rule 2 by closing thecircuits energizing these lamps.

A module selection device 18 interposed between the switching member 14and the counter 9 causes the counter counting module to vary as afunction of different measurements. Thus, the counter may count from 5to 5 when it displays speeds, or units (or tenths) when the pulsefrequency varies from 100 to 6,250 Hz (measurement of temperatures orpressures). A device 19 disposed between the voltmeter 17 and thedisplay device 11 causes the sign + or - of voltmeter 17 to be displayed(for example in the case of positive or negative temperatures). Anotherdevice 20 connecting the switch 14 to the display unit 11 is providedfor displaying the decimal point or the degree (°) sign when thedisplayed value corresponds to temperature; finally, a last device 21connected to the preceding one 20 and to the display means 11 controlsthe extinction of the useless zero on the left-hand of the lastsignificant figure, or the maintaining of the zero preceding the decimalpoint.

A dimmer or device 22 for adjusting the luminous intensity is associatedwith the display means 11. It may consist of a system comprising aphoto-resistor 29 adapted to adjust automatically the luminous intensityas a function of the surrounding luminosity. This system is providedwith time-lag or delay means so that in case of sudden change in thesurrounding luminosity this variation cannot react immediately on thesystem, thus eliminating stray effects.

By night or in case of low surrounding luminosity, the system is set ina manner to permit the easy reading of the displayed data at any time.

An alarm system 23 connected on the one hand to the interfaces 13 of thevarious probes or pickups 12 and on the other hand to the switchingmember 14 is provided for permanently comparing voltages at the outputof the interfaces corresponding to the pickups with reference voltages.Beyond predetermined thresholds, the visual alarm and possibly the soundalarm is energized as already explained in the foregoing.

Various members and devices of the block diagram of FIG. 2 aretransistorized electronic devices already known per se but separately; astabilized supply device 24 delivers the various stabilized voltagesnecessary for operating the assembly. These various devices and membersare assembled into a compact electronic casing and interconnected byusing the integrated circuit method. This casing is mounted in closevicinity of the instrument panel of FIG. 1 and connected threretothrough a simple electric cable of any suitable length.

The luminous display panel according to this invention mayadvantageously be combined with a rear view mirror disposed in front ofthe windscreen, in the field of vision of the driver. The rules 1 and 2surround in this case the mirror proper 25, as shown in FIG. 3, and theelectronic casing mentioned in the preceding paragraph may beincorporated therein. The panel may be further completed byincorporating a pilot lamp 5g displaying the symbol "M.p.H." (or"Km.p.H.") illuminated when the vehicle speed is displayed.Alternatively, a luminous scale 26 may be inserted for example along onevertical side of the frame for displaying permanently in a known fashionthe vehicle speed in the form of a sequence of light spots the number ofwhich is proportional to the magnitude to be displayed. These spots mayconsist of electroluminescent diodes or incandescent lamps. The scale 26may be provided, if desired, with masks of different colors, orelectro-luminescent diodes emitting lights of different colors forsignalling a danger or a speed-limit. Thus, for example, green spots maybe used for displaying the vehicle speed up to 30 or 50 m.p.h.(according to the local official town traffic regulation), yellow spotsbetween this limit and an upper one, for example 70 or 80 m.p.h. andthen red spots beyond this last limit.

The addition of luminous scales may also be contemplated for signallingthe various sequences illustrated by the luminous symbols 5a to 5f.

In this combination form of embodiment the flat screen of a televisionreceiver may be substituted for the conventional rear view mirror, thenumeric data and other measurement signs being displayed by thesuperimposition of characters or signs to the image of the road behindthe vehicle. This permits the positioning of the display panelassociated with this television receiver screen at a proper location infront of the windscreen, so that it is better adapted to the field ofvision of the driver. Thus, the latter can see at any time what is goingon behind his vehicle and at the same time observe on the display panelall the measurements appearing thereon.

Other combinations may be contemplated by those conversant with the artwithout departing from the basic principles of the invention as setforth in the appended claims.

What is claimed as new is:
 1. An electronic-display instrument panel formotor vehicles, adapted to display values of data signals emitted fromsensing devices detecting various parameters of functions and physicalconditions, comprising a frame and at least first and second smalldisplay panels incorporated in the frame, a signal pulse counter, thefirst display panel comprising a luminous digit display means connectedto said counter for displaying values of counted pulses, the seconddisplay panel comprising conventional symbol designs and means forilluminating said designs, said symbol designs being associated with thedisplayed values, said instrument panel further comprising a clockmember connected to said counter for emitting constant periodic signalsduring which pulses received by said counter are counted, a plurality ofmeans connected to said sensing devices for converting voltages of datasignals emitted by said sensing devices into other signals to betransmitted to said counter, said converting means including a firstmeans for converting the voltage of the signals of a first sensingdevice emitting frequency pulses, and a plurality of second means forconverting the voltage of signals of the other sensing devicesconcerning a plurality of parameters, a first switching member,connected to said first means for converting, for transmitting to saidcounter data concerning a single function parameter and on request dataconcerning sequences of different parameters, a multiple secondswitching member having a plurality of switches which are connected tosaid plurality of second means for converting and said second displaypanel, a third means connected to said first and second switchingmembers and to said clock member for converting into frequency pulsesthe voltage of signals transmitted by said second means for converting,means for selecting data sequences concerning a plurality of parametersof functions and physical conditions and connected to said clock memberand to said first and second switching members, means connected to saidsequences selecting means for starting on request under the control ofthe vehicle driver switching of different data sequences, meansconnected to said luminous display means for adjusting the luminousintensity of the display on said first display panel, and meansconnected to said second means for converting the voltage of signals ofsensing devices and to said second multiple switching member forenergizing by priority alarm devices when predetermined thresholds ofthe values displayed for various parameters are overstepped.
 2. Aninstrument panel according to claim 1 wherein said means forilluminating said designs on said second display panel includes pilotlamps.
 3. An instrument panel according to claim 1 wherein said symboldesigns of said second display panel corresponding to the parameters offunctions and physical conditions detected by said sensing devices,comprises an alpha-numeric system illuminating said designs.
 4. Aninstrument panel according to claim 1 wherein said luminous displaymeans comprises an alpha-numeric system adapted to display the result ofthe counting operation of said counter.
 5. An instrument panel accordingto claim 1 wherein colored transparent masks cover said symbol designs.6. An instrument panel according to claim 1 wherein said means forselecting selects automatically the order and number of the datasequences.
 7. An instrument panel according to claim 1 wherein saidpulse counter is associated with an integrated circuit connected to saidfirst switching member for receiving emitted signal pulses and to saidsecond switching member through a module selecting device for varyingthe counter as a function of said various parameters.
 8. An instrumentpanel according to claim 1 wherein said means for adjusting the luminousintensity of said luminous display means of said first display panel isa dimmer connected with said luminous display means and comprising aphoto-resistor controlling the voltage of current energizing saidluminous display means for adjusting automatically and with a certaintime-lag said luminous intensity as a function of the luminositysurrounding the panel.
 9. An instrument panel according to claim 1wherein said first and second means for converting the signals emittedby said sensing devices comprise for each sensing device an interfacefor converting the signal voltage, and said third means for convertingsignals comprises a digit voltmeter converting into frequency pulses thevoltage of signals received from the interfaces connected to the sensingdevices, said digit voltmeter being controlled by said second multipleswitching member and synchronized by said clock member.
 10. Aninstrument panel according to claim 9 wherein said alarm devices areassociated with said interfaces for sensing devices detecting thevarious functions and also with said second multiple switching memberand compare between the voltages transmitted by said interfaces andreference voltages so as to give a priority, with regard to any involveddisplay data, to a predetermined threshold in connection with thiscomparison, while causing flickering of corresponding pilot lampsilluminating a corresponding symbol design on said second display panel.11. An instrument panel according to claim 9 wherein said luminousdisplay means comprises a means for displaying the sign + or - from saiddigit voltmeter, another means associated with said second switchingmember for displaying a degree sign and a decimal point, and a devicefor extinguishing non-significant figures associated with said means fordisplaying a degree sign and a decimal point.
 12. An instrument panelaccording to claim 1 wherein a rear view mirror mounted in front of thevehicle windscreen is associated with the instrument panel, said firstand second display panels surrounding said mirror.
 13. An instrumentpanel according to claim 12 wherein said mirror comprises the screen ofa television receiver.
 14. An instrument panel according to claim 12further comprising a graduated luminous scale for displaying at leastone parameter value.
 15. An instrument panel according to claim 14wherein said display scale is made in different colors.
 16. Aninstrument panel according to claim 14 wherein colored fixed framescover said scale.
 17. An instrument panel according to claim 14 whereincolored movable frames cover said scale.